CVE-2026-4519
webbrowser.open() allows leading dashes in URLs
At a glance
- Severity
- HIGH 7.0
- EPSS
- EPSS 0.31 % · percentile 24 (2026-10-27)
- State
- PUBLISHED
- Published
- Updated
- Assigner
- PSF
- NVD status
- Modified
Description
The webbrowser.open() API would accept leading dashes in the URL which could be handled as command line options for certain web browsers. New behavior rejects leading dashes. Users are recommended to sanitize URLs prior to passing to webbrowser.open().
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 4.0 | HIGH 7.0 | CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N | PSF |
| CVSS 3.1 | HIGH 7.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L | redhat-SADP |
| CVSS 4.0 | HIGH 7.0 | CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD · cna@python.org (Secondary) |
| CVSS 3.1 | LOW 3.3 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N | NVD · nvd@nist.gov (Primary) |
| CVSS 3.1 | HIGH 7.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L | NVD · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Secondary) |
Weaknesses (CWE)
European references
- ENISA EUVD · EUVD-2026-13712
- GCVE · GCVE-0-2026-4519
CERT-FR advisories
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0958 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0667 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0556 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0492 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0368 — Vulnérabilité dans les produits Microsoft · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0335 — Vulnérabilité dans CPython · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:python:python:*:*:*:*:*:*:*:*< 3.13.13cpe:2.3:a:python:python:*:*:*:*:*:*:*:*≥ 3.14.0 < 3.14.4cpe:2.3:a:python:python:3.15.0:alpha1:*:*:*:*:*:*cpe:2.3:a:python:python:3.15.0:alpha2:*:*:*:*:*:*cpe:2.3:a:python:python:3.15.0:alpha3:*:*:*:*:*:*cpe:2.3:a:python:python:3.15.0:alpha4:*:*:*:*:*:*cpe:2.3:a:python:python:3.15.0:alpha5:*:*:*:*:*:*cpe:2.3:a:python:python:3.15.0:alpha6:*:*:*:*:*:*cpe:2.3:a:python:python:3.15.0:alpha7:*:*:*:*:*:*
Affected products
| Product | Versions |
|---|---|
| Python Software Foundation · CPython | affected 0 < 3.10.21 ; affected 3.11.0 < 3.11.16 ; affected 3.12.0 < 3.12.14 ; affected 3.13.0 < 3.13.13 ; affected 3.14.0 < 3.14.4 ; affected 3.15.0a1 < 3.15.0a8 |
References
- https://github.com/python/cpython/pull/143931
- https://github.com/python/cpython/issues/143930
- https://mail.python.org/archives/list/security-announce@python.org/thread/AY5NDSS433JK56Q7Q5IS7B37QFZVVOUS/
- https://github.com/python/cpython/commit/43fe06b96f6a6cf5cfd5bdab20b8649374956866
- https://github.com/python/cpython/commit/82a24a4442312bdcfc4c799885e8b3e00990f02b
- https://github.com/python/cpython/commit/9669a912a0e329c094e992204d6bdb8787024d76
- https://github.com/python/cpython/commit/ad4d5ba32af4d80b0dfa2ba9d8203bfb219e60a5
- https://github.com/python/cpython/commit/ceac1efc66516ac387eef2c9a0ce671895b44f03
- https://github.com/python/cpython/commit/cbba6119391112aba9c5aebf7b94aea447922c48
- https://github.com/python/cpython/commit/3681d47a440865aead912a054d4599087b4270dd
- https://github.com/python/cpython/commit/591ed890270c5697b013bf637029fb3e6cd2d73e
- https://github.com/python/cpython/commit/594b5a05dc9913880ac92eded440defbf32a28d1
- https://github.com/python/cpython/commit/89bfb8e5ed3c7caa241028f1a4eac5f6275a46a4
- https://github.com/python/cpython/commit/96fc5048605863c7b6fd6289643feb0e97edd96c
- https://github.com/python/cpython/commit/cc023511238ad93ecc8796157c6f9139a2bb2932
- http://www.openwall.com/lists/oss-security/2026/03/20/1
- https://access.redhat.com/security/cve/CVE-2026-4519
- https://bugzilla.redhat.com/show_bug.cgi?id=2449649
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4519.json
- https://access.redhat.com/errata/RHSA-2026:10102
- https://access.redhat.com/errata/RHSA-2026:9614
- https://access.redhat.com/errata/RHSA-2026:9745
- https://access.redhat.com/errata/RHSA-2026:13812
- https://access.redhat.com/errata/RHSA-2026:7244
- https://access.redhat.com/errata/RHSA-2026:6256
- https://access.redhat.com/errata/RHSA-2026:19064
- https://access.redhat.com/errata/RHSA-2026:19019
- https://access.redhat.com/errata/RHSA-2026:6473
- https://access.redhat.com/errata/RHSA-2026:6281
- https://access.redhat.com/errata/RHSA-2026:6283
- https://access.redhat.com/errata/RHSA-2026:9387
- https://access.redhat.com/errata/RHSA-2026:9621
- https://access.redhat.com/errata/RHSA-2026:9386
- https://access.redhat.com/errata/RHSA-2026:9289
- https://access.redhat.com/errata/RHSA-2026:9591
- https://access.redhat.com/errata/RHSA-2026:9261
- https://access.redhat.com/errata/RHSA-2026:9262
- https://access.redhat.com/errata/RHSA-2026:9260
- https://access.redhat.com/errata/RHSA-2026:10101
- https://access.redhat.com/errata/RHSA-2026:9042
- https://access.redhat.com/errata/RHSA-2026:10111
- https://access.redhat.com/errata/RHSA-2026:9354
- https://access.redhat.com/errata/RHSA-2026:9705
- https://access.redhat.com/errata/RHSA-2026:7010
- https://access.redhat.com/errata/RHSA-2026:6766
- https://access.redhat.com/errata/RHSA-2026:6286
- https://access.redhat.com/errata/RHSA-2026:6285
- https://access.redhat.com/errata/RHSA-2026:19216
- https://access.redhat.com/errata/RHSA-2026:19175
- https://access.redhat.com/errata/RHSA-2026:19177
- +21 more
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |